Content area
Full text
ABSTRACT:
Vaccines are considered as the most successful medical invention against various infectious diseases. However, there are significant barriers for improving immune response especially with recombinant vaccines. Therefore, immunopotentiators (adjuvants) are included in vaccine formulation in order to augment immune response. The present study was aimed to alter the alum type adjuvant for hepatitis B vaccine. The hepatitis B vaccine was encapsulated in dextran microparticles by emulsion cross linking technique. The formulated microparticles were characterized in terms of morphology, particle size analysis and in vitro release study. In this study we could not demonstrate the dextran microparticle system as an adjuvant for HBsAg.
KEYWORDS: HBsAg, Dextran, microparticle system.
INTRODUCTION:
Controlled release of vaccines in the naive form for prolonged duration that converts the multiple dose vaccine regimens into single dose vaccines may represent an important advancement towards the betterment of human health care and welfare. The development of vaccine delivery systems prepared from biodegradable polymers has received considerable attention and many researchers evaluated various biodegradable polymers during past two decades. Globally, hepatitis B is a significant health problem and leads to one million deaths annually from liver failure, cirrhosis and hepatocellular carcinoma1. Currently available hepatitis B vaccines are immunogenic, efficacious and safe. But the immune response varies with individual and declines with increasing age. Yet there is justification for producing more immunogenic vaccines that could eventually be more efficacious in defined groups such as non responders to yeast derived vaccines or travelers and health care workers who need rapid protection even after a priming dose of vaccine. The concept of HBsAg vaccine delivery system has been reported by Sivakumar et al., 2010 and 20082,3.
In this study dextran sulphate polymer is used to encapsulate the HBsAg and various parameters were established.
MATERIALS AND METHODS:
Materials
Dextran sulfate sodium salt (Mw 40,000) was purchased from Sigma Aldrich, USA, recombinant HBsAg (alum free, 3mg/ ml) was provided as a gift sample by Serum Institute of India, Pune. All the other chemicals were of analytical grade.
Preparation of microparticles
Extensive pre-formulation studies were carried out in order to encapsulate HBsAg in the dextran microparticles. In this research work, the dextran microparticles were developed by emulsion cross linking technique. Briefly, 1% w/v solution of dextran was prepared...